Four-dimensional picture of the fetus at 5 and a half months of pregnancy 1. Baby\’s size and development At 5 and a half months of pregnancy, the baby has grown to about 16cm in length and weighs about 240g. At this time, the baby\’s body proportions are relatively harmonious, and the head circumference, chest circumference, and abdominal circumference are basically matched. The baby\’s ribs, skull, pelvis and other bones have begun to form, and muscles and subcutaneous fat are also gradually increasing. After these few months of growth, the baby\’s head is relatively large, about 1/3 of the body length, and the leg length is relatively short, about 1/4 of the body length. The baby\’s various organs are also beginning to form and develop at this time, such as the liver, heart, lungs